1. Field of the Invention
The present invention relates to a robot simulator and a method of controlling a robot simulator, and in particular, to a robot simulator that simulates movement of a robot having a plurality of figures and displays an image of a movable area of the robot.
2. Description of the Related Art
There has been known a conventional robot that involves two-dimensional motions consisting of linear motion and rotational motions. This kind of robot can be conceptually shown as in FIGS. 1A and 1B to 3A and 3B.
As shown in FIG. 1A and FIG. 1B, a robot 15 that has, for example, an Xθ mechanism includes a linear movement section 52, a rotation driving section 53, and an arm 54. The linear movement section 52 is configured by a linear actuator. The rotation driving section 53 is displaced in an X direction (horizontal direction in FIG. 1A and FIG. 1B) by the linear movement section 52. The rotation driving section 53 includes a base that is a center of rotation. A tip of the rotation driving section 53 is the arm 54 that moves such as to rotate in a θ direction. A tool 55 is mounted on a tip of the arm 54. The tool 55 is positioned by a base of the arm 54 being moved in the X direction and a tip end of the arm 54 being rotated in the θ direction around a Z axis.
In this case, as shown in FIG. 2A, the robot 15 is given a plurality of figures (or control figures) to be selected with respect to a position (in two dimensions) or a posture (in three dimensions) of the tool 55 selectably mounted to an end of the arm 54 at different axial positions in the X (axial) direction. In this example, the figures of the robot 15 are divided into a right-hand system and a left-hand system depending on a position (axial position) to which the base of the arm 54 moves on an X axis and a position of the end of the arm 54 relative to the base of the arm 54 in the X direction. In other words, the right-hand system is used when the end of the arm 54 is positioned to the left side with respect to the base of the arm 54 in the X direction (see FIG. 2A). The left-hand system is used when the end of the arm 54 is positioned to the right side with respect to the base of the arm 54 in the X direction (see FIG. 2A).
As a result, a movable area of the robot 51 is divided into three areas: an area operable by only the right-hand system (Area 1); an area operable by only the left-hand system (Area 3); and an area operable by both the left-hand and right-hand systems (Area 2) (see FIG. 2B). Therefore, the operable area in the movable area of the robot 51 differs depending on the control configuration.
When an obstacle 56 is present, as shown in FIG. 3A and FIG. 3B, within the movable area of the robot 51 configured as described above, depending on the position, shape, and size of the obstacle 56, an area in the periphery of the obstacle 56 that is beyond the reach of the arm 54 and in which movement (operation) is not possible differs between when the figure of the robot 51 is the right-hand system (FIG. 3A) and when the figure is the left-hand system (FIG. 3B). An area in which movement is not possible by both the right-hand system and the left-hand system is also present.
As a result, distribution of the above-described inoperable areas is difficult to grasp intuitively. Therefore, if the distribution of the inoperable areas, described above, or the operable areas excluding the inoperable areas can be grasped before the robot 51 is set and actually operated, a programming operation or a teaching operation can be efficiently performed.
For example, a technology is disclosed in Japanese Patent Laid-open Publication No. 7-214485 in which the movement of the robot is simulated and displayed in a display device.
However, in the invention described in Japanese Patent Laid-open Publication No. 7-214485, the operable areas or the inoperable areas are not displayed in adherence to when the figure of the robot 51 differs. A display configuration of the invention described in this publication No. 7-214485 shows the overall robot 51 as a perspective view, and displays the movement of the robot 51 in adherence to a program in a three-dimensional manner.
In a display configuration such as this, whether an inoperable area is present can only be determined by a result of simulated movement of a robot 1. Therefore, as shown in FIG. 8, when the operable area differs depending on the system, the distribution of the areas becomes difficult to grasp dearly. Improved efficiency of the programming operation and the teaching operation cannot be achieved.